Compounded hydrocarbon oil



Patented Aug. 19, 1941 COMPOUNDED HYDROCARBON 01L John T. Rutherford andRobert J. Miller, Berkeley, CaliL, assignors to Standard Oil Company ofCalifornia, San Francisco, Calif., a corporation of Delaware No Drawing.Application May 6, 1939, Serial No. 272.154

24 Claims.

This invention relates to a new and useful composition of matter andinvolves a composition comprising a hydrocarbon, such as a viscoushydrocarbon oil, and a polyvalent metal salt of sulfur containingsubstituted acids of phosphorus.

The production of improved hydrocarbon oils and particularly oflubricating oils having desired characteristics has been the subject ofextensive research and investigation in recent years. Generallyspeaking, the compounding of hydrocarbon oils to obtain desiredcharacteristics involves empirical phenomena and the action of untestedtypes of compounding agents cannot be predicted.

A characteristic which has been the subject of extensive investigationis the tendency of hydrocarbon oils to deteriorate or partiallydecompose the Dies'el type, is the tendency of the elite cause or permitthe sticking of piston rings.

The crankcase lubricant in internal combustion engines is subjected toextremely severe I operating conditions and in engines of the Dieseltype the lubricant encounters in the piston ring zone temperatures offrom approximately 425 to 650 F. and pressures from the oxidizingcombustion gases as high as 750 to 1150 lbs. per sq. in. Addition agentswhich render hydrocarbon oils resistant to deterioration by heat at hightemperature levels in the orde of those above mentioned usually impartto the oil the ability to inhibit piston ring sticking in internalcombustion engines and permit longer periods of operation of suchengines without the necessity of major overhauls heretofore occasionedby stuck piston rings.

It should be noted that stabilizing agents which are eiiective at lowtemperatures to impart increased stability to hydrocarbon oils, or whichare effective at temperatures even as high as 200 or 250 F., are oftenineffective under the more severe operating conditions and highertemperature levels to which lubricating oils are subjected in Dieselengines. Thus the operativeness of a stabilizer at atmospherictemperatures, or even temperatures as high as 200 to 300 F., gives noadequate basis for predicting the action of the same stabilizing agentat materially higher temperatures and under more severe operatingconditions. The disclosures in the prior art relative to suchstabilizers therefore cannot serve as a guide for one seekingstabilizing'agents or oxidation inhibitors effective at highertemperature levels. The phenomena involved are catalytic in nature, arehighly empirical and require extensive experimentation to determine theaction of a given type of addition agent.

The present invention involves the discovery that dispersion ofpolyvalent metal salts of sulfur containing substituted acids ofphosphorus in hydrocarbon oils, such as mineral lubricating oil, impartsnew, unpredictable and highly desirable properties to the composition.These new properties render the compounded oil particularly useful forvarious purposes. Although increased resistance to deterioration at hightemperature levels comprises one of the principal advantages of thecompounded oil of this invention, it is to be understood that theinvention is not limited to this feature, that difierent compounds ofthe general type herein involved vary in their degree of effectivenessand may impart one or more other desirable properties to the lubricatingcomposition. In eneral, however, it has been dis-- covered that the newcompositions herein disclosed are more stable to heat than is ahydrocarbon oil with which the compositions are compounded. The newcompositions of this invention are therefore useful where resistance todeterioration by heat is important. An example of such utility otherthan as a lubricating oil comprises use as a heat transfer fluid whereit may be desirable to inhibit or prevent the formation of a deposit onthe metal surfaces from or to which heat is being conveyed. Likewise,the increased resistance to oxidation imparted to oils on these bearingmetals.

the oil by the compounds of this invention will find variousapplications as, for instance, in insulating, switch or transformeroils.

It has also been discovered that certain metal salts of sulfurcontaining substituted phosphori acids have a combination of propertiesheretotore unknown and particularly desirable in compounded mineraloils, namely, the ability to inhibit oxidation and impart to lubricatingoils increased resistance to deterioration by heat, the ability toinhibit piston ring sticking, freedom from the production of increasedwear on cylinder walls and piston rings as compared with uncompoundedmineral oils, low corrosivity as respects the chemical action of thecompounded oil on bearing metals, such as cadmium-silver and copper-leadalloys, as well as the power to inhibit the corrosive action of highlyparafllnic Although various compounded mineral oils are known which arecapable of inhibiting piston ring sticking, the discovery of specificcompounding agents capable of imparting the above combination of properties to hydrocarbon oils represents an unobvious and importantcontribution.

Salts of sulfur-containing substituted acids of phosphorus which may beadded to hydrocarbon where M is a metal selected from Groups II, III,

IV and VI of Mendelyeevs Periodic Table of the Elements. Specificexamples of such metals are calcium, barium, strontium, aluminum,chromium, lead and magnesium. Within the broader aspects of theinvention M may also be selected from the group iron, cobalt, nickel,zinc and tin. In the above formula, B may bealkyl, aryl, alkaryl,aralkyl or cyclic non-benzenoid groups; x and Y each are either sulfuror oxygen and sulfur; H is hydrogen; P is phosphorus; a, b, d and erepresent small whole numbers and c may be zero or a small whole number.

The metal salts of this invention are preferably formed from substitutedacids of pentavalent phosphorus of one or more of the following typeformulae:

monothioester of phosphoric acid;

di-thio ester of phosphoric acid;

di-ester of teira-thiophosphoric acid;

monothioester oi tetra-thiophosphoric acid;

di-thio ester of tetra-thiophosphoric acid;

monoestcr of mono-thiophosphoric acid;

dl-estcr of mono-thiopliosphoric add:

where R and R may be alkyl, aryl, alkaryl, aralkyl or cyclicnon-benzenoid groups. Substituted acids containing at leastapproximately 12 carbon atoms are preferred. Examples of preferred typeacids are alkyl or alkaryl sulfur containing substituted phosphoricacids having at least 12 carbon atoms in the molecule. However, it is tobe understood that the broader aspects of the invention include othertypes of sulfur containing substituted acids of phosphorus containingmore than 12 carbon atoms. Additional examples of such acids which maybe used in forming the metal salts of the present invention' are asfollows:

mono-thioester of phosphonic acid 7 mono-ester of trithiophosphonic acidmono-thioester of trithiophosphonic acid.

In all of the above formulae R and B may be alkyl, aryl, alkaryl,aralkyl or cyclic non-benzenoid groups.

In general, polyvalent metal salts of sulfur containing substitutedderivatives of acids of phosphorus such as phosphorous acid, HaPOa;hypophosphoric acid, HzPOs; orthophosphorlc acid, H3PO4; pyrophosphoricacid, H4P2O7; monothiophosphoric acid, H*PSO: di-thiophosphoric acid,HsPSzOa; trithiophosphoric acid, HaPSsO; tetra-thiophosphoric acid,H3PS4; thiopyrophosphoric acid, H4PzS1; and trithiopyrophosphoric acid,H4P2S'O4 fall within the broadest aspects of the invention. Bysubstituted acids or substituted derivatives of phosphorus, wheneverused herein, it is intended to designate acids of .phosphorus containingan organic group of the inum cetyl thiophosphate, lead cetylthiophosphate, calcium cetyl phenyl thiophosphate, chromium cetyl phenylthiophosphate, aluminum cetyl phenyl thiophosphate, lead cetyl phenylthiophosphate.- Salts such as calcium thio-cresyl phosphate, chromiumthio-cresyl phosphate, aluminum thio-cresyl phosphate, and leadthio-cresyl phosphate, although less effective than the previouslyrecited compounds, improve various properties of the oil, particularlyits resistance to oxidation.

Additional examples of salts within the scope of the invention arealuminum lauryl thiophosphate, aluminum octadecyl thiophosphate,aluminum spermol thiophosphate, aluminum oleyl thiophosphate, aluminumspermenyl thiophosphate, aluminum di-(amyl phenyl) thiophosphate,aluminum naphthenyl thiophosphate, aluminum di-cyclohexanylthiophosphate, aluminum tetra-chlorooctadecyl thiophosphate, aluminumdi-(6-chloro, 2-phenyl phenyl) thiophosphate, aluminum di-(3-methyl,4-chlorophenyl) thiophosphate, calcium lauryl thiophosphate, calciumoctadecyl thiophosphate, calcium spermol thiophosphate, calcium oleylthiophosphate, calcium spermenyl thiophosphate, calcium di-(amyl phenyl)thiophosphate, calcium naphthenyl thiophosphate, calcium di-cyclohexanylthiophosphate, calcium tetra-chloro-octadecyl thiophosphate, calciumdi-(fi-chloro, 2-phenyl phenyl) thiophosphate, calcium di-(3-methyl,4-chlorophenyl) thiophosphate, barium lauryl thiophosphate, bariumoctadecyl thiophosphate, barium spermol thiophosphate, barium oleylthiophosphate, barium spermenyl thiophosphate, barium di-(amyl phenyl)thiophosphate, barium naphthenyl thiophosphate, barium di-cyclohexanylthiophosphate, barium tetra-chloro-octadecyl thiophosphate, bariumdi-(6-chloro, Z-phenyl phenyl) thiophosphate, barium di-(3-methyl, 4-chloro-phenyl) thiophosphate, chromium lauryl thiophosphate, chromiumoctadecyl thiophosphate, chromium spermol thiophosphate, chromium oleylthiophosphate, chromium spermenyl thiophosphate, chromium di-(amylphenyl) thio phosphate, chromium naphthenyl thiophosphate, chromiumdi-cyclohexanyl thiophosphate, chromium tetra-chloro-octadecylthiophosphate, chromium di-(fi-chloro, Z-phenyl phenyl) thiophosphate,chromium di-(3-methyl, 4-chlorophenyl) thiophosphate, lead laurylthiophosphate, lead octadecyl thiophosphate, lead spermol thiophosphate,lead oleyl thiophosphate, lead spermenyl thiophosphate, lead di-(amylphenyl) thiophosphate, lead naphthenyl thiophosphate, leaddi-cyclohexanyl thiophosphate, lead tetrachloro-octadecyl thiophosphate,lead di (6- chloro-2-phenyl phenyl) thiophosphate, lead di- (3-methyl,4-chloro-phenyl) thiophosphate, magnesium lauryl thiophosphate,magnesium octadecyl thiophosphate, magnesium spermol thiophosphate,magnesium oleyl thiophosphate, magnesium spermenyl thiophosphate,magnesium di (amyl phenyl) thiophosphate, magnesium naphthenylthiophosphate, magnesium di-cyclohexanyl thiophosphate, magnesiumtetra-chloro-octadecyl thiophosphate, magnesium di-(S-chloro, 2-phenylphenyl) thiophosphate, magnesium di- (3-methyl, 4-chloro-phenyl)thiophosphate.

It should also be understood that the sulfur containing substitutedacids of phosphorus uti lized for preparing the metal salts of thisinvention may contain organic substituents other than pure hydrocarbongroups. The organic radical in the acid of phosphorus may comprise, inaddition to carbon and hydrogen, substituents such as the halogenschlorine or bromine, hydroxy, sulfhydryl and similar groups. Likewise,the sulfur in the sulfur containing atom need not necessarily bedirectly attached to the phosphorus atom. An acid which illustratesthese types of compounds comprises the phosphoric acid ester ofdi-(p-hydroxy phenyl) sulfide.

The acids of phosphorus utilized in the present composition may beprepared by various methods. For example, a mixture of a higher alcoholand phosphorus pentasulfide, a mercaptan and phosphorus pentoxide, amercaptan and phosphorus pentasulfide or a three-component mixture suchas a mercaptan, phosphorus pentoxide and pyrophosphoric acid, may bedirectly fused in proportions to give acid esters. The reaction by whichthe substituted phosphoric acid is formed in the last mentionedthree-component mixture is believed to be represented by the followingequations:

For example, thio-cresyl phosphoric acid may be prepared by reactingthio-cresol with phosphorus pentoxide and pyrophosphoric acid at atemperature not in excess of 250 F. The thio-cresol is charged to astainless steel mixer equipped with a jacket. Steam is admitted in thejacket until a temperature of 200 F. is reached, at which temperaturethe phosphorus pentoxide and pyrophosphoric acid are added. Water iscirculated through the jacket at this time to control the reactiontemperature. Stirring is continued until the reaction is complete andthe product withdrawn.

In preparing the metal salts involved herein the alkali metal salt ofthe above acid may be dissolved in aqueous solution and the heavy metalor alkaline earth metal salt precipitated therefrom. For instance, thecalcium salt may be manufactured by precipitation as follows: Water andcaustic potash are charged to a mixer and heated to a temperature of 180F. The acid is added, thereby formingan alkali salt. An aqueous calciumchloride solution is incorporated with violent agitation duringprecipitation to prevent inclusion of the potassium salt. Theprecipitated curd is washed free of inorganic salts with hot freshwater. Mineral oil is then added and the solution is dehydrated as byheating to a temperature of 300-330 F. The concentrated oil solution soobtained may conveniently be used for mixing or blending with other oilsto prepare the completed product.

Either normal or basic aluminum salts may be prepared by theprecipitation method. The

normal salts will contain three equivalents of the acid per atom ofaluminum, whereas the basic salt should contain less than threeequivalents of the substituted acid of phosphorus.

Calcium salts may also be prepared in a nonaqueous environment as by thereaction of calcium carbide with the free substituted acid to giveacetylene and the anhydrous calcium salt. Aluminum salts may likewise beprepared in an environment substantially free of water by the reactionof aluminum chloride with the free substituted acid of phosphorus. Suchaluminum salts have properties different from the salts prepared byprecipitation in aqueous solutions. Although these latter salts areuseful, aluminum salts prepared by precipitation from aqueous solutionsare preferred where the ability to inhibit piston ring sticking inlubricating oils is the property desired.

By way of illustration and to demonstrate the unusual propertiespossessed by the compounded Table I lubricating oils under severeoperating conditions,

such as those encountered in the lubrication of Compound Method ofmanufacture of acid Oxidator test: c.c. Hours Percent oxygen to sticksalt absorbed piston in 2.5 rings hours COMPOUNDED IN ACID REFINEDWESTERN OIL S. A. E. 30

Mineral oil -Q o 324 Calcium phosphate ofp-hydroxydip-Hydroxfidiphenylsulfide and P105 1 76 sulfide. +phospoleum.

phenyl Calcium thiocresyl hos hate Calraigum cetylthiop osp ate CetylalcohoH-Pa o do Chromium cetylthiofihosphat Cetyl alcohol+PzSa Leadcetylthiophosp ate Cetyl alcohol+P1Sa 1 Do .d .05 148 Calciumcotylphenylthiophosphate. Cetyl phenol+P2Ss l 170 Calciumthiocresylthiophosphate. Th1ocrcso1+PaSs 1 76 Thiocresol andP1s05+phospholeum i 108 (1.5 hr.) v 110 COMPOUNDED IN PENNSYLVANIA OILS. E. 30

Mineral oil 0 302 45 Calcium cetylphenylthiophosphete.-. l 180 Do 165+Calcium cctyiphenylthiophosphate+ 5+. 12o

calcium cetylphcnate. Calcium thiccresylthiophosphats... Thiocresol+PiSsl 188 It will be observed that all of the compounding agents wereeffective to very substantially inhibit the absorption of oxygen in, anddeterioration of, the mineral lubricating oil in the oxidator test. Thistest is described by Dornte in the Journal of Industrial and EngineeringChemistry, 1936, vol. 28, page 26, and was carried out in the presentexamples at 340 R, which represents very severe conditions.

In the piston ring sticking tests a single cylinder, 2%" bore, 2 stroke,Lauson gasoline en gine was operated under extremely severe conditionsfor the purpose of developing fully piston ring sticking and pistongumming tendencies under circumstances simulating severe operatingconditions encountered in the field. Operation of the motor during testwas continuous at 1600 R. P. M. except for periodic shut-downs atfifteenhour intervals for inspection. The jacket ternperature wasmaintained at approximately 375 F. and the sump oil temperature atapproximately 220 F. during the test.

The compounding agents herein disclosed may have one or more advantages,depending upon the particular compound selected, the proportionutilized, and the environment which the lubricating oil is to encounter.It should be observed, for example, that even though a compounded oilmay be somewhat corrosive to copper-lead or cadmium-silver bearingmetals, Babbitt bearings are little, if at all, affected by suchcorrosive action. Hence, compounded oils which may not be particularlydesirable for lubrication of copper-lead or cadmium-silver bearings maybe highly useful and extremely advantageous in conjunction with theoperation of internal combustion engines hav- 7 pistons and piston ringsof internal combustion engines of the Diesel type, polyvalent metalsalts of sulfur containing substituted acids of pentavalent phosphoruscontaining more than twelve carbon atoms in the molecule and preferablycontaining an alkyl or alkaryl substituent should be utilized. It is tobe understood that by polyvalent metal salts" used inthe aboveconnection the alkaline earth metals are included and the termpolyvalent metal is adopted to distinguish from the alkali metals.

A moderately acid refined Western naphthenic base oil is the preferredoil stock used as a base for the compounded lubricants involved herein.The compounding ingredients appear to function more efficiently in sucha base 011 than in a highly parafiinic oil stock or a highly refinedWestern oil. However, it is to be understood that the invention is notlimited to any particular base stock since various of the presentcompounds are more eflicient in inhibiting oxidation and corrosioneffects in highly parafilnic oil stocks than any compounds so fartested.

The proportion of metal salts of substituted acids of phosphorus addedto mineral lubricating oils may vary widely depending upon the usesinvolved and the properties desired. As little as 0.05% by weight of thecompound gives measurable improvements, particularly as respectsinhibiting oxidation and color stability of the compounded oil. Fromapproximately 0.25 to approximately 2% of the compound may be added tolubricants where increased stability'in internal combustion engines andresistance to erties desired. Solutions containing more than 2% of thecompounds in mineral oil may be utilized for the purpose of.preparinglubricating greases and concentrates-capable of dilution withlubricating oils and the like. Such higher concentrations comprise aconvenient method of handling the compounds and may be used as additionagents for lubricants in general as well as for other purposes.

The metal salts of this invention may be added I to hydrocarbon oilscontaining other compounding ingredients such aspour point depressors,oilmess agents, extreme pressure addition agents,

blooming agents, compounds for enhancing the viscosity index of thehydrocarbon oil, corrosion inhibitors andthe like. The invention in itsbroader aspects embraces mineral hydrocarbon oils containing, inaddition to metal salts of the substituted acids of phosphorus,thickening agents and/or metal soaps in proportions or in amountsinsufficien-t to form greases, as in the case of mineral castor machineoils or other compounded liquid lubricants.

The compounds of this invention may be added to oils other thanhydrocarbon lubricating .oils, for example, fuel oils or non-dryingvegetable or animal oils.

While the character of the invention has been described in detail andnumerous examples of the composition given, this has been done by way ofillustration only and with the intention that no limitation should beimposed on the invention hereby. It will be apparent to those skilled inthe art that numerous modifications and variations of the illustrativeexamples may be effected in the practice of the invention which is ofthe scope of the claims appended hereto.

We claim:

1. A composition of matter comprising a hydrocarbon oil subject todeterioration at elevated temperature and a polyvalent metal salt of asulfur containing substituted acid of phosphorus having an organicsubstituent therein, said salt being present in an amount suificientsubstantially to inhibit said deterioration.

2. A composition of matter comprising a hydrocarbon oil and more thanapproximately 0.05% by weight based on the oil of a chromium salt of asulfur containing substituted acid-oi phosphorus having an organicsubstituent therein.

3. A composition of matter comprising a hydrocarbon oil and more thanapproximately 0.05% by weight based on the oil of an aluminum salt of asulfur containing substituted acid of phosphorus having an organicsubstituent therein. y l l d. A composition of matter comprising ahydrocarbon oil and more than approximately 0.05% by weight based on theoil of a lead salt of a sulfur containing substituted acid of phosphorushaving an organic substituent therein.

5. A composition of matter comprising a hydrocarbon oil subject todeterioration at elevated temperatures and a polyvalent metal salt of asulfur containing substituted acid of pentavalent phosphorus having anorganic substituent therein,.said salt being present in an amountsufficient substantially to inhibit said deterioration.

6. A composition of matter comprising a hydrocarbon oil and more thanapproximately 0.05% by weight based on the oil of a chromium salt of asulfur containing substituted acid of pentavalent phosphorus having anorganic substituent therein.

7. A composition of matter comprising a hydrocarbon oil and more thanapproximately 0.05% by weight based on the oil of an aluminum salt of asulfur containing substituted acid of pentavalent phosphorus having anorganic substituent therein.

8. A composition of matter comprising a hylubricating oil and more thanapproximately 0.05% by weight based on the oil of a polyvalent metalsalt of a sulfur containing substituted acid of phosphorus having anorganic substituent therein.

10. A stabilized-liquid lubricant comprising a lubricating oil and morethan approximately 0.05% by weight based on the oil of a polyvalentmetal salt of a sulfur containing substituted acid of pentavalentphosphorus having an organic substituent therein.

11. A composition of matter comprising a hydrocarbon oil subject todeterioration in the presence of oxygen and a polyvalent metal salt of athioesterof phosphoric acid, said salt being present in an amountsufilcient substantially to inhibit said deterioration.

12. A composition of matter comprising a hydrocarbon oil subject todeterioration in the presence of oxygen and a chromium salt of athioester of phosphoric acid, said salt being present in an amountsufficient substantially to inhibit said deterioration.

13. A composition of matter comprising a hydrocarbon oil subject todeterioration in the presence of oxygen and an aluminum salt of athioester of phosphoric acid, said salt being present in an amountsuficient substantially to inhibit said deterioration.

14. A composition of matter comprising a hydrocarbon o-il subject todeterioration in the presence of oxygen and a lead salt of a thioesterof phosphoric acid, said salt being present in an amount suificientsubstantially to inhibit said deterioration.

15. A composition of matter comprising a hydrocarbon oil subject todeterioration in the presence of oxygen and a polyvalent metal salt ofan ester of a thio-phosphoric acid, said salt being present in an amountsufilcient substantially to inhibit said deterioration.

, 16. A composition of matter comprising a hydrocarbon oil subject todeterioration in the presence of oxygen and a chromium salt of an esterof a thio-phosphoric acid, said salt being present in an amountsuflicient substantially to inhibit said deterioration.

17. A composition of matter comprising a hydrocarbon oil subject todeterioration in the presence of oxygen and an aluminum salt of an esterof a thio-phosphoric acid, said salt being present in an amountsuflicient substantially to inhibit said deterioration.

18. A composition of matter comprising a hydrocarbon oil subject'todeterioration in the presence of oxygen and a lead salt of an ester of athio-phosphoric acid, said salt being present in an amount sufiicientsubstantially to inhibit said deterioration.

19. A composition of matter comprising a hydrocarbon oil subject todeterioration in the presence of oxygen and a polyvalent metal salt of astituted acid of pentavalent phosphorus having more than approximatelytwelve carbon atoms in the molecule.

22. A compounded lubricant comprising a lu- I,

an aluminum salt of a sulfur-containing substituted acid of pentavalentphosphorus having more than approximately twelve-carbon atoms in themolecule.

24. A compounded lubricant comprising a lubricating oil and fromapproximately 0.05% to approximately 2% by weight based on the oil or alead salt of a sulfur-containing substituted acid of pentavalentphosphorus having more 7 than approximatelytwelve carbon atoms in themolecule.

JOHN T. RUTHERFORD. ROBERT J. MILLER.

DISCLAIMER 2,252,984.JOIm T. Rutherford HYDROCARBON OIL.

and Robert J. Miller, Berkeley, Calif. COMPOUNDED Patent dated August19, 1941.

Disclaimer filed May 10, 1944, by the assignee, Standard Oil Company ofCalifornia. Hereby enters this disclaimer to claims 1, 4, 5, 8, 11, 13,14, 15, 17, 18, 19, 20,

and 24 of said patent.

[Oficial Gazette Jane 20, 1944.]

DISCLAIMER 2,252,984.J0hn T. Rutherford and Robert J. Miller, Berkeley,Calif. COMPOUNDED HYDROCARBON 011.. Patent dated August 19, 1941.Disclaimer filed May 10, 1944, by the assignee, Standard Oil Company ofCalifornia. Hereby enters this disclaimer to claims 1, 4, 5, 8, 11, 13,14, 15, 17, 18, 19, 20, and 24 of said patent.

[oflic'ial Gazette June 20, 1944.]

